Networking Models, TCP/IP, and OSI – Practice Flashcards

A collection of question-and-answer flashcards covering key concepts from the lecture on TCP/IP and OSI networking models, including layers, protocols, encapsulation, PDUs, and interactions between layers.

Which protocols are examples of TCP/IP transport layer protocols?

TCP and UDP

Which protocols are examples of TCP/IP data-link layer protocols?

Ethernet and PPP

What type of interaction occurs when HTTP asks TCP on the same device to send data?

Adjacent-layer interaction

When TCP on one computer numbers a segment and the other computer acknowledges it, what interaction is this?

Same-layer interaction

What networking process is illustrated when a web server adds TCP, IP, and data-link headers (and trailer) to data?

Data encapsulation

In data-link terminology, what is the name of the PDU that includes both a header and a trailer?

Frame

In OSI terms, what alternative name can be used instead of “frame”?

Layer 2 PDU

What term describes a comprehensive grouping of protocols and standards that let devices communicate, such as TCP/IP or OSI?

Networking model

What is a set of logical rules that devices must follow to communicate?

Protocol

What documents, published mainly by the IETF, formally propose and document Internet standards and protocols?

RFCs (Requests for Comments)

Name three example protocols that operate at the TCP/IP application layer.

HTTP, POP3, and SMTP

Name the two primary protocols of the TCP/IP transport layer.

TCP and UDP

Name two example protocols that operate at the TCP/IP network (Internet) layer.

IP and ICMP

Give two example technologies that operate at the TCP/IP data-link & physical layer.

Ethernet and 802.11 (Wi-Fi)

What is the main role of the application layer in the TCP/IP model?

To provide services that applications need, without defining the application itself

Why does TCP include an error-recovery feature?

To guarantee delivery of data using acknowledgments and retransmissions

What does TCP do when a segment with a particular sequence number is not acknowledged?

Retransmits the missing segment

What does adjacent-layer interaction refer to in networking?

How adjacent layers on the same device collaborate, with the lower layer providing services to the higher layer

What does same-layer interaction refer to in networking?

How the same protocol layer on two different devices communicates using that layer’s headers

How are protocols distributed across the TCP/IP layers?

The application layer has many protocols, while the transport and network layers have fewer, with TCP, UDP, and IP being the primary ones

Why does IP define addresses?

To uniquely identify each device and organize addresses like postal codes

What is the process of forwarding an IP packet based on its destination address called?

IP routing

How do the data-link and physical layers of TCP/IP relate?

The physical layer defines how signals travel over media, and the data-link layer sets rules for sending data over that media

What service does the data-link layer provide to the network layer?

It moves packets to the next host or router across the physical medium

In networking, what does encapsulation mean?

Adding headers (and sometimes trailers) by each layer to the data from the layer above

What is the correct order of encapsulation in the TCP/IP model?

Application → Transport → Network → Data-link → Physical

Match the encapsulated terms to their layers: Segment, Packet, Frame.

Segment – Transport layer; Packet – Network layer; Frame – Data-link layer

Which OSI layer corresponds to the Internet layer of TCP/IP?

Network layer (Layer 3)

What is the primary function of the Transport layer?

Providing reliable data transfer between hosts

Which OSI layer handles data formatting and encryption and lacks a direct counterpart in TCP/IP?

Presentation layer

In the TCP/IP model, which layer combines the OSI Application, Presentation, and Session functions?

Application layer

How is the relationship between the OSI and TCP/IP models usually described?

TCP/IP is a practical implementation, whereas OSI is a theoretical framework

What does the term Protocol Data Unit (PDU) mean in the OSI model?

Encapsulated data (header, trailer, and payload) at a specific layer

What is de-encapsulation?

Interpreting and removing lower-layer headers to reveal higher-layer data

What is a “frame” in networking?

A data-link layer structure consisting of a header, trailer, and encapsulated data

What is a “packet” in networking?

A network-layer PDU that includes the IP header and encapsulated data but not lower-layer headers or trailers

What is a “segment” in networking?

A transport-layer (TCP) PDU that includes a TCP header and encapsulated data, possibly formed by dividing larger data into smaller pieces

In networking, what does a networking model represent?

A set of protocols and standards that enable devices to communicate

In the context of PDUs, what does the term specifically exclude?

Headers and trailers from lower layers

What does same-layer interaction between devices rely on to communicate?

The headers defined by that layer